When rebuilding my bike from a carb overhaul I found #16 laying loose with nowhere to go, so anybody want to help me out?



Story goes -
My 2000 F4 is rubbish below 3000rpm and after cleaning the carbs once to no avail I pulled them a 2nd time to clean and install a DynoJet stage 1 kit to match my slip on exhaust / K&N filter then sync'd the carbs, but she still runs like crap below 3000rpm!

Pilot jets are spotless!

 

Sorry man but I cannot tell where either end of that hose goes. I do know that the system in the photo is designed to force air directly, it bypass' the main air filter and once you reach 25 mph the the valve will close and the bike will use the main air system. I removed the entire secondly air system and it improved my bikes responsiveness. Talk to boyo he know a good amount about that.

 

The way #16 hose looks could be a breather type hose that hangs to atmosphere..

With it running crap under 3k revs to me that sounds like lean running
from what i remember about having a carbed bike...

 

What Snakezz said. There's a bunch of breather hoses that dangle below and this is one of them.

I had a similar problem as you, we were talking about it in a previous thread I made, and I solved it. The person before me installed the dynojet kit and made the carbs spotless, but didn't replace the pilot jets. So I bought #42 pilot jets, probably should have gone to a #45 but eh, and I synced the bike to the best of my ability and it was fixed. They're $20, just make sure you buy the right series. I have an F4 and its a keihin pilot jet 21 series which has the threads higher up on the thicker part.

Seems like a fuel problem right? So I'm assuming its the carbs or anything fuel is going through going from the tank to the carbs.

 

Thanks guys some good info.
My thoughts are because it started to happen suddenly with no modifications it can't be running lean, now I've fitted the jet kit it should run more rich but have still to get a good run before pulling the plugs.

Although the pilot jets have been cleaned twice I might replace them anyway to be sure.

I'm interested in the sub-air system now, now going to check if my solenoid is opening!

 

Crap, my solenoid valve is opening as soon as the ignition is turned on so now I'm back to square one.